Absorption refrigeration apparatus



-May 1s, 1965v G A.GRUBB l Re. 25,782

ABSORPTION REFRIGERATION APPARATUS ZBY JINVENTOR.

Arran/vir May 18, 1965 G. A. GRUBB Re. 25,782

BSORPTION REFRIGERATION APPARATUS Original Filed Aug. 29. 1961 5Sheets-Sheet 2 INVENTOR.

uw @wp/ZM May 18, 1965 G. A. GRUBB ABSORPTION REFRIGERATION APPARATUS ssheets-sheet s Grignal Filed Aug. 29, 1961 INV TOR. im MEM huw/yf 4Arramvfr United States Patent O 25,782 ABSQRPTION REFRIGERATIONAPPARATUS Gunnar Axel Grubb, Broxnma, Sweden, assigner to AktiebolagetElectrolux, Stockholm, Sweden, a corporation of Sweden Original No.3,093,978, dated June 18, 1963, Ser. No. 134,760, Aug. 29, 1961.Application for reissue June 12, 1964, Ser. No. 386,470

Claims priority, application Sweden Sept. 22, 1960 12 Claims. (Cl.62-236) Matter enclosed in heavy brackets 1 appears in the originalpatent but forms no part of this reissue specification; matter printedin italics indicates the additions made by reissue.

My invention relates to absorption refrigeration apparatus of the kindin which vapor is expelled out of solution by heating.

Itis an object of the invention to provide for absorption refrigerationapparatus improved heating structure for conveniently heating theapparatus by different sources of heat.

Another object is to provide for a vapor-expulsion unit of absorptionrefrigeration apparatus an electrical heating element and a fluid fuelburner for heating a heating tube of heat receiving structure andcontrolling the sources of heat for selectively rendering either theelectrical heating element or the fuel burner operable to heat theheating tube.

A further object is to provide a duid fuel burner and several electricalheating elements adapted to be energized with different kinds ofelectrical energy for heating a heating ue of heat receiving structureof absorption refrigeration apparatus and controlling the sources ofheat for selectively rendering a single source of heat operable to heatthe heating tube.

The invention, together with the above and other objects and advantagesthereof, will be more fully understood upon reference to the followingdescription and the accompanying drawing forming a part of thisspecification, and in which:

FIG. 1 illustrates more or less diagrammatically parts of absorptionrefrigeration apparatus to which the invention is applied, the apparatusbeing shown in an upright space at the rear of a refrigerator andadapted to be operated by a fluid fuel burner;

FIG. 2 is a View similar to FIG. l with the refrigeration apparatusadapted to be operated by an electrical heating unit;

FIG. 3 is a fragmentary sectional view taken at line 3-3 of FIG. 1;

FIGS, 4 and 5 are elevational views of electrical heating units like theheating unit shown in FIG. 2;

FIG. 6 is a fragmentary perspective view of a detail which may beembodied at the rear of the refrigerator shown in FIGS. l and 2; and

FIG. 7 is a fragmentary view taken at line 7-7 of FIG. 1.

Referring to FIG. l, the invention is shown in connection with arefrigerator which comprises a cabinet 10 supported on legs 11. Thelateral side walls 12 of the cabinet extend rearward beyond a rear plate14 to provide a vertical compartment 15 in which parts of absorptionrefrigeration apparatus are housed. During operation of therefrigeration apparatus, natural draft circulation of air is induced toeffect air-cooling of an absorber 16 and a condenser (not shown), suchcooling air flowing upward through an opening 17 in the bottom Re.25,782 Reissued May 18, 1965 ice of the cabinet and passing throughopenings 18 in an apertured rear part of the top 19 of the cabinet.

The absorption refrigeration apparatus is of a uniform pressure typecontaining an inert gas or pressure equalizing gas. Refrigerant vapor isexpelled from absorption liquid in a vapor lift pipe 20 of avapor-expulsion unit 21 and passes through the upper part of a standpipe22 and a conduit 23 to a condenser. The refrigerant vapor, such asammonia, is liquefied in the condenser and ows into an evaporator inwhich the refrigerant evaporates and diffuses into an inert gas, such ashydrogen, to produce a refrigerating effect within the thermallyinsulated interior of the cabinet 10. The resulting gas mixture ofrefrigerant and inert gas liow from the evaporator to an absorber whichmay be of an air-cooled type including the coil 16 and an absorbervessel 24 to which the lower end of the coil is connected, such gasmixture entering the absorber vessel 24 through a conduit 25.

In the absorber refrigerant is absorbed from the gas mixture intoabsorption liquid, such as Water, which is delivered thereto through aconduit 26, and the absorption liquid enriched in refrigerant passesinto the absorber vessel 24. The inert gas is returned from the absorberto the evaporator in the path of iiow including a conduit 27, and theenriched absorption liquid is conducted through a conduit 28 and innerpipe 29 of a liquid heat exchanger 30 to the vapor-expulsion unit 21.

The absorption liquid from which refrigerant vapor has been expelledtiows by gravity from standpipe 22 through the outer pipe 32 of liquidheat exchanger 30 and conduit 26 into the upper part of absorber coil16. The liquid surface level A maintained in standpipe 22 is at a higherlevel than the region at which liquid is introduced into absorber 16from the upper end of conduit 26. ln order to simplify the drawing, thecondenser, evaporator and connections therefor have not been shown, suchparts being well known and their illustration not being necessary for anunderstanding of this invention.

Absorption solution enriched in refrigerant flows from the absorbervessel 24 through conduit 28 and inner pipe 29 of liquid heat exchanger30 into the lower end of vapor lift pipe 20 which is in thermal exchangerelation with a heating tube 33 at 34, as by welding, for example.

The part of the pump or lift pipe 20 in thermal exchange relation withthe heating tube 33 may be referred to as the vapor-forming part inwhich vapor bubbles are formed due to heat derived from the heatingtube. Due to the formation of these vapor bubbles which tend to collectand become larger and larger, liquid in the vapor lift pipe 20 becomessegregated, whereby slugs of liquid are caused to rise in the lift pipeby vapor lift action. Vapor generated in the vapor lift pipe 20 flowsfrom the upper end thereof through the upper part of standpipe 22 intoconduit 23 and passes to the condenser, as previously explained.

The vapor-expulsion unit 21 in its entirety, together with a majorportion of the liquid heat exchanger 30, are embedded in a body ofinsulation 35 retained in a metal shell o-r casing 36 having an opening37 at the bottom thereof, the shell being rectangular or circular inhorizontal cross-section. The heating tube 33, which is embedded in theinsulation 35, is formed with an enlarged bottom section 33a whichprojects through the bottom opening 37 in the casing 36. The upper endof the heating tube 33 projects through a top opening 38 in the casing35 and includes an extension 33h which terminates at the top 19 of thecabinet. The rear part of the top 19 of the cabinet is provided with aremovable apertured section 19a having an opening 19h through which theupper extension 33b of the heating tube eXtends.

As shown in FIG. 1, a gaseous fuel burner 40, which may be supported inany suitable manner in the enlarged bottom section 33a of the heatingtube 33, is provided with a burner head 40a positioned at the top partof the enlarged tube section. A gap of suitable size is formed betweenthe burner 40 and bottom heating tube section 33a to provide a passagefor secondary air which will insure complete combustion of the mixtureof gaseous fuel and primary air discharged from the burner head 46a. Theburner 40 is connected to a source of supply of gaseous fuel by a pipe41 in which is connected a valve 42. The burner 40 serves as a gusburner heating element operable to maintain a flame burning in theatmosphere for producing combustion gases at an elevated temperature andcapable of functioning to heat the heut receiving par! or tube 20 of thevapor expulsion unit 21 to expel vapor out of solution therein by heutderived from the combustion gases substantially at the elevatedtemperature.

In accordance with my invention, the heating tube 33 may be employed asa component part of heating structure adapted to be employed with agaseous fuel burner in the manner just described and illustrated in FIG.l; and also as a component part of heating structure adapted to beemployed with an electrical heating unit in the manner illustrated inFIG. 2. In FIG. 2, in which parts similar to those shown in FIG. 1 anddescribed above are referred to by the same reference numerals, anelectrical heating element 43a is positioned Within the heating tube 33.The heating tube 33 snugly receives the heating elernent 43a which maycomprise a cartridge housing an elec- :rical `wire or the like having arelatively high resistance :hat generates heat when connected to asource of electri- :al energy.

The heating element 43a forms the bottom part of a sortable heating unit44a which is positioned within the ieating ltube 33 [form] from itsupper open end. The ieating unit 44a includes a narrower upper part 45awhich nay be formed of suitable insulating material and a collar ravinga tlange 46a for holding the heating unit at the up- )er open end oft-he heating tube 33. The heating unit 44a s of such length that theheating element 43a will be posiioned in that part of heating tube 33 towhich the pump )r lift pipe 20 is heat conductively connected thereto ati4. As shown in FIG. 4, the heating unit 44a is conrected by anelectrical cord 47a to a terminal fitting or lug 48a adapted to beconnected to an outlet socket 49a rovided in any suitable manner in theupper part of the ear vertical compartment of the cabinet 10.

In accordance with my invention, I provide the heating init 44a for theheating tube 33 which is adapted to be onnected to a conventional sourceof electrical supply Sti nd a second heating unit 44h for the heatingtube 33 /hich is adapted to be connected to a battery 51. When heheating unit 44a is positioned in the heating tube 33 nd its terminaltting 48a is connected to the outlet ocket 49a, a circuit will becompleted for the heating lement 43a when switch 52 is closed. From oneside of 1e source of electrical supply 50 this circuit ywill includeonductors 53, 54, switch 52 and conductor S5 4back to 1e other side ofthe source of electrical supply Si).

The heating unit 44b for battery operation is similar to 1e heating unit44a and includes a heating element 43h, rsulating portion 45h, collar46h, cord 47b and terminal tting 48h, When the heating unit 44b ispositioned in 1e heating tube 33 and its terminal fitting 48b isconected to an outlet socket 49h, a circuit will be completed r theheating element 43h when switch 56 is closed. rom one terminal .of thebattery 51 this circuit will inude conductors 57 and 58, switch 56 andconductor 59 ick to the other terminal of the battery.

Plates 64) and 6l, which are respectively fixed to the top 1d bottom ofthe casing 36, are apertured to receive a :rtical shaft or rod 62.towhich is fixed a collar 63 adapted to rest on the top plate 60. The rodor snaft 62 is provided with a control knob 64 at its upper end. To apart of the shaft 62 below the knob 64 and above top plate 66 is xed anarm 65. A ilat horizontal part 66 which projects radially outward fromthe periphery of the arm 65 can be moved into and from a slotted portion67 of the heating flue extension 33h.

The valve 42 for controlling the supply of gaseous fuel to the burner 40includes a casing 42a of cylindrical shape which may be fixed to thebottom plate 61. Within the casing is positioned a rotatable valvemember 42h iixed to the shaft 62. The valve member 42h is formed with apassage 42o which connects the pipe 41 and burner 4t] when the valvemember is in the position illustrated in FIG. 3.

Each -of the switches 52 and 56 may comprise a member of cylindricalshape which is formed of electrically conductive material and liXed tothe shaft 62 and insulated therefrom in any suitable manner. Brushes 54aand 55a, to which the conductors 54 and 5S are connected, are adapted tolbear against the periphery of switch 52; and brushes 56a and 59a, towhich the conductors 58 and 59 are connected, are adapted to bearagainst the periphery of switch 56. The peripheries of the switchmembers 52 and 56 are provided with insulating sections 52a and 56a,respectively, over which the brushes move for a part of each completeturn of the shaft 62.

When the knob 64 is turned so that valve 42 will be open and in theposition illustrated in FIG. 3 to deliver gaseous fuel to the burner 49,the outer flat part 66 of arm 65 will be positioned in the slottedportion 67 of the heating tube extension 33h. Therefore, when it isdesired to operate the refrigeration apparatus with the gas burner 40,it is necessary to remove either one of the heating units 44a or 44bfrom the heating llue 33 if this already has not been done. Also, theflat member 66 projecting into the heating tube extension 33a during gasoperation of the refrigeration apparatus will prevent anyone frompositioning a heating unit in the heating tube. During gas operation,the heating units 44a and 44h may be stored in the rear apparatuscompartment 15. As shown in FIGS. l, 2 and 7, the plate 60 is formedwith a pair of openings 68 through which the heating units may beinserted, the anges 46a and 46h of the heating units being suflicientlylarge to engage the plate 60 :at the openings and support the heatingunits.

Desirably, the relationship of valve member 42h and the insulatingsections 52a and 56a of the switches is such that in a rst position ofknob 64 the valve 42 is partly or fully open and the brushes engage theinsulating sections 52a and 56a of the switch members 52 and 56, and ina second position o-f knob 64 the valve 42 is close-d and the brushesare removed from the insulating sections 52a and 56a :of the switchmembers. Hence, the control knob 64 can be moved either to one of twopositions, namely, a rst valve on position, or a second position whichwill render either one of the heating units 44a or 44h operable toeffect heating of the refrigeration apparatus when it is positioned inthe heating tube 33. In the second position .of control knob 64 the iiatpart 66 of arm 65 will be in the position illustrated in FIG. 2ttobpermit a heating unit to be inserted into the heating In FIGS. 4 and5 it will be seen that the terminal fitting 46a for the heating unit 44ais provided with round pins 69a While the terminal fitting 48h for theheating unit 44h is pro-vided with flat blade 69h. The outlet socket 49aassociated with the conventional source of electrical supply 50 isformed with round openings 49a adapted to receive the pins 69a of theterminal fitting 48a, while the outlet socket 49h associated with thebattery 51 is formed with narrow rectangular slots 49h adapted toreceive the llat blades 69h of the terminal fitting 48h. Hence, theheating units 44a and 44h, each of which is designed to operate with aparticular kind of electrical energy, cannot inadvertently be connectedto the wrong kind Aof electrical energy.

The outlet sockets 49a and 49h may be positioned in the rear apparatuscompartment in diierent walls 70 and 71 which are perpendicular to oneanother, as shown in FIG. 6. The outlet sockets may be placed close tothe junction of the walls 76 and 71 so that when the terminal fitting ofone heating unit is connected to its outlet socket, that terminalfitting will be located in front of the other outlet socket and preventthe other terminal fitting from being positioned therein. Hence, evenwhen the control knob 64 is moved to such a position that either one ofthe electrical heating units will be rendered operable to effectoperation of the refrigeration apparatus, only one of the heating unitscan be connected to its associated source of electrical supply when theoutlet sockets are located in the rear apparatus compartment in themarmer illustrated in FIG. 6 and described above.

By providing the removable apertured section 19a at the rear part of thetop of the cabinet, easy access to the upper part of the rear storagespace can be obtained to manipulate control knob 64 and shift anelectrical heat- 'ing element from the heating flue 33 to the plate 60-for storage in one of the openings 68 therein or from such storageposition to the heating flue 33. In vew of the foregoing, it will now beunderstood that the gas pipe 4] functions as a means for supplying gasenergy in the form of a combustible gas to the burner 40, and that theelectrical conductors 53, 54 and 55 function as a means for conductingelectrical energy to the electrical heating unit 44a. In FIGS. 1 and 2the switch mechanism 52 and valve mechanism 4Z and controls operativelyassociated with these mechanisms constitute means for selectivelyconnecting the gas pipe 41 to the burner 40 or the electrical conductorsto the electrical heating element 43a whenever both electricity and gasare available as sources of power for the refrigeration system. Theshaft 62 which is provided with the control knob 64 and to which theapertured rotatable valve member 42h and switch mechanism 52 are hxedform components of the selective connecting means and may be operated atwill to obtain the desired source of power for the refrigeration unit.

As explained above, the rod 62 is operable to actuate the valvemechanism 42 at will to connect the gas pipe 41 to the burner 40 onlywhen the electrical conductors 53, 54 and 55 are disconnected from thesource of electrical supply 50 by the switch mechanism 52; and the rod62 is operable to actuate the switch mechanism 52 to energize theheating element 43a from the source of electrical supply 50 only whenthe gas pipe 4Z is disconnected from the burner 40 by the valvemechanism 42.

While l have shown and described a single embodiment of my invention, itwill be apparent that modiiications and changes may be made withoutdeparting from the spirit and scope of the invention, as pointed out inthe following claims.

I claim:

l. In absorption refrigeration apparatus, an upright shell having anupstanding side wall and a top and bottom and insulation therein, avapor-expulsion unit embedded in the insulation, said vapor-expulsionunit having at least one part in which vapor is expelled from solutionby heating, an upright heating tube which extends through saidinsulation between the top and bottom -of said shell, the top and bottomof said shell having openings communicating with the upper and lowerends of said heating tube, means heat conductively connecting theexterior surfaces of said tube and said part along a zone which extendslengthwise of said tube, said heating tube being hollow, an electricalheating element, means for removably positioning said heating element insaid tube through its upper open end to locate said heating elementvertically at said zone for operating the apparatus electrically, meansincluding a fluid fuel burner positioned at the lower end of saidheating tube for operating the apparatus with a combustible fuelmixture, the part of said heating tube at said zone having its innersurface in the path of flow of combustion gases produced duringoperation of the burner, and control means for rendering said electricalheating element operable to heat said heating tube and for renderingsaid fluid fuel burner operable to heat said heating tube, saidelectrical heating element being removed from said heating tube at itsupper end when said uid fuel burner is rendered operable to heat saidheating tube, said control means including structure for blocking saidheating tube to prevent the insertion of said electrical heating elementtherein responsive to rendering said fluid fuel burner operable to heatsaid heating tube.

2. In absorption refrigeration apparatus, an upright shell having anupstanding side wall and a top and bottom and insulation therein, avapor-expulsion unit embedded in the insulation, said vapor-expulsionunit having at least one part in which vapor is expelled from solutionby heating, an upright heating tube which extends through saidinsulation between the top and bottom of said shell, the top and bottomof said shell having openings communicating with the upper and lowerends of said heating tube, means heat conductively connecting theexterior surfaces of said tube and said part along a zone which extendslengthwise of said tube, said heating tube being hollow, an electricalheating element, means for removably positioning said heating element insaid tube through its upper open end to locate said heating elementvertically at said zone for operating the apparatus electrically, meansincluding a fluid fuel burner positioned at the lower end of saidheating tube for operating the apparatus with a combustible fuelmixture, the part of said heating tube at said zone having its innersurface in the path of flow of cornbustion gases produced duringoperation of the burner, control means for rendering said electricalheating element operable to yheat said heating tube and for renderingsaid fluid fuel burner operable to heat said heating tube, saidelectrical heating element being removed from said heating tube at itsupper end when said uid fuel burner is rendered operable to heat saidheating tube, an electrical circuit for said electrical heating elementhaving switch means and a fluid fuel line for said burner having avalve, and said control means including a manually operable part at thevicinity of the upper open end of said heating tube which is movable totwo positions, said control means being effective to close said switchmeans and shut said valve in one position of said -part and to open saidswitch means and open said valve in the other position of said part. I

3. In absorption refrigeration apparatus, an upright shell having anupstanding side wall and a top and bottom and insulation therein, avapor-expulsion unit embedded in the insulation, said vapor-expulsionunit having at least one part in which vapor is expelled from solutionby heating an upright heating tube which extends through said insulationbetween the top and bottom of said shell, the top and bottom of saidshell having openings cornmunicating with the upper and lower ends ofsaid heating tube, means heat conductively connecting the exteriorsurfaces of said tube and said part along a zone whicl extendslengthwise of said tube, said heating tube being hollow, an electricalheating element, means for removably positioning said heating element insaid tube througl its upper open end to locate said heating elementverti` cally at said zone for operating the apparatus electrically meansincluding a fluid fuel burner positioned at the loWe: end of saidheating tube for operating the apparatus witl a combustible fuelmixture, the part of said heating tubi at said zone having its innersurface in the path of ov of combustion gases produced during operationof thl burner, control means for rendering said electrical heat ingelement operable to heat said heating tube and fo rendering said fluidfuel burner operable to heat said heat ing tube, said electrical heatingelement being remove from said heating tube at its upper end when saidfluit fuel burner is rendered operable to heat said heating tube,another electrical heating element and an electrical circuit for each ofsaid elements, switch means for each of said circuits, and a fluid fuelline for said burner having a valve, and said control means including amanually movable part which is movable to two positions, said controlneans being effective to close both of said switch means and shut saidvalve in one position of said part and to open )oth of said switch meansand open said valve in the other Josition of said part, each of saidelectrical circuits havng an outlet socket, each of said electricalheating elenents having a terminal fitting, said outlet sockets beingaositioned so that either terminal fitting in its outlet socket villprevent the other outlet socket from receiving the lther terminalfitting.

4. A refrigerator comprising a cabinet having an apraratus space at anupright wall thereof, an apertured art, means for removably supportingsaid apertured part Iver the apparatus spaced at the top of the cabinet,re-

rigeration apparatus including an upright shell positioned 1 theapparatus space, said shell having an upstanding ide wall and a top andbottom and insulation therein, a apor-expulsion unit embedded in theinsulation, said vaor-expulsion unit having at least one part in whichvapor expelled from solution by heating, an upright heating .lbe whichextends through said insulation between the )p and bottom of said shell,the top and bottom of said lell having openings communicating with theupper and )wer ends of said heating tube, the upper end of said eatingtube terminating at the vicinity of the top of the ibinet, means heatconductively connecting the exterior lrfaces of said tube and said partalong a zone which (tends lengthwise of said tube, said heating tubebeing allow, an electrical heating element, means for remov- Jlypositioned said heating element in said tube through s upper open end tolocate said heating element ver- :ally at said zone for operating theapparatus electrically, eans including a iiuid fuel burner positioned atthe wer end of said heating tube for operating the apparas with acombustible fuel mixture, the part of said heatg tube at said zonehaving its inner surface in the path `ow of combustion gases producedduring operation of e burner, control means for rendering saidelectrical :ating element operable to heat said heating tube and rrendering said iiuid fuel burner operable to heat said l.ating tube,said electrical heating element being rcoved from said heating tube atits upper end when said lid fuel burner is rendered operable to heatsaid heating be, and said control means including a manually movlecontrol part in the apparatus space at the vicinity of e upper end ofsaid heating tube, said control part being cessible upon removal of saidapertured part. 5. Apparatus as set forth in claim 4 which includesother electrical heating element and an electrical cirit for each ofsaid elements, switch means for each of .d circuits and a fuel line forsaid burner having a valve, d movable control part being movable to twoposins, said control means being effective to close both of d switchmeans and shut said valve in one position of d control part and to openboth of said switch means d open said valve in the other position ofsaid control rt, each of said electrical circuits having an outlet :ketin the upper part of the apparatus space, means the upper part of theapparatus space for storing at st one of said electrical heatingelements, and said ctrical heating elements having terminal fittingswhich er from one another, and one of said outlet sockets eiving onlyone of said terminal fittings and the other said outlet socketsreceiving only the other of said ninal fittings. i. In absorptionrefrigeration apparatus, an upright ll having an upstanding side walland a top and bot- 1 and insulation therein, a vapor-expulsion unitemlded in the insulation, said vapor-expulsion unit havat least one partin which vapor is expelled from 75 solution by heating, an uprightheating tube which extends through said insulation between the top andbottom of said shell, the top and bottom of said shell having openingscommunicating with the upper and lower ends of said heating tube, meansheat conductively connecting the exterior surfaces of said tube and saidpart along a zone which extends lengthwise of said tube, said heatingtube being hollow, an electrical heating element, means for removablypositioning said heating element in said tube through its upper open endto locate said heating element vertically at said zone for operating theapparatus electrically, means including a fiuid fuel burner positionedat the lower end of said heating tube for operating the apparatus with acombustible fuel mixture, the part of said heating tube at said zonehaving its inner surface in the path of fiow of combustion gasesproduced during operation of the burner, control means for renderingsaid electrical heating element operable to heat said heating tube andfor rendering said fluid fuel burner operable to heat said heating tube,said electrical heating element being removed from said heating tube atits upper end when said fluid fuel burner is rendered operable to heatsaid heating tube, said heating tube being formed with an opening in itswall, and said control means including a part movable into the interiorof said heating tube through the opening in its wall to block theinsertion of said electrical heating element therein responsive torendering said fluid fuel burner operable to heat said heating tube.

7. In combination with a refrigerating system of the type alternativelyemploying gas or electricity as power sources and in which cooling iseected by a refrigeration unit having u heat receiving part, of a gusburner heating means adapted to heut the heut receiving part, means forsupplying gas energy to scid burner heating means, electrical heatingmeans adapted to heat the heut receiving part, means for conductingelectrical energy to said electrical heating means, valve means in saidgas energy supply means, switch means in said electrical energyconducting means, means for controlling said switch means and said valvemeans to render said electrical heating means operable to heat the heatreceiving part or to render said burner heating means operable to heatthe heat receiving part, said control means including u member rotatableabout an axis to first and second positions, said valve means includinga rotatable element which forms a unitary port of said rotatable member,said rotatable member having a portion which is operatively associatedwith said switch means, said control means being ejecn've to close saidswitch means and shut said valve means upon movement of said rotatablemember to said first position and to open said switch means and opensaid valve means upon movement of said rotatable member to said secondposition.

8. In combination with a refrigerating system of the type alternativelyemploying gas or electricity as power sources and in which cooling iseected by u refrigeration unit having a heat receiving part, of a gasburner heating element adapted to heat the heat receiving part, meansfor supplying gus energy to said burner heating element, an electricalresistance heating element adapted to heat the heut receiving pdrt,means for conducting electrical energy to said resistance heatingelement, and switching means connected to said gas energy supply meansand to said electrical energy conducting means and adaptedsimultaneously to connect a first of said energy means to its associatedheating element and to disconnect the second of said energy means fromits associated heuting element or to connect the second of said energymeans to its associated heating element and to disconnect the first ofsaid energy means from its associated heating element, said switchingmeans comprising an electrical switch which is coupled to saidelectrical energy conducting means und to said resistance heatingelement and includes a movable parl for completing and interruptingelectrical continuity therethrough, a rotatable member operativelyassociated with said movable part of said switch for closing said switchto complete electrical continuity therethrough at first particularangular orientations of said rotatable member and to interruptelectrical continuity at other orientations of said rotatable member, avalve having a rotatable plug with a passage therethrough, said valvebeing coupled to said gas energy supply means and to said gas burnerheating element for permitting the flow of gas through said valve atsecond particular orientations of said rotatable plug and forobstructing the flow of gas through said valve at other orientations ofsaid rotatable plug, and means for simultaneously rotating saidrotatable member and said rotatable plug, said rotatable member and saidrotatable plug being disposed such that a fixed angular diyerence ismaintained between said first and second particular angularorientations.

`9. In combination with a refrigerating system of the type alternativelyemploying gas or electricity as power sources and in which cooling iseected by a refrigeration unit having a heat receiving part, of a gasburner heating element adapted to heat the heat receiving part, meansfor supplying gas energy to said burner heating element, an electricalresistance heating element adapted to heat the heat receiving part,means fo'r conducting electrical energy to said resistance heatingelement, and switching means connected to said gas energy supply meansand to said electrical energy conducting means and adaptedsimultaneously to connect a first of said energy means to its associatedheating element and to disconnect the second of said energy means fromits associated heating element or to connect the second of said energymeans to its associated heating element and to disconnect the first ofsaid energy means from its associated heating element, said switchingmeans comprising an electrical switch which is coupled to saidelectrical energy conducting means and to said resistance heatingelement and includes a movable part for completing and interruptingelectrical continuity therethrough, a rotatable shaft, a member mountedon said shaft and rotatable therewith, said rotatable member beingope'ratively associated with said movable part of said electrical switchfor closing said switch to complete electrical continuity therethroughat first particular angular orientations of said rotatable member and tointerrupt electrical continuity at other orientations of said rotatablemember, a valve having a plug with a passage therethrough, said valvebeing coupled to said gas energy supply means and to said burner heatingelement for permitting the flow of gas through said valve at secondparticular angular orientations of said rotatable plug and forobstructing the flow of gas through said valve at other orientations ofsaid rotatable plug, said plug being mounted on said shaft and rotatabletherewith, said rotatable member and said plug being mounted on saidshaft such that said first and second particular orientations occur atdierent angular positions of said shaft.

10. In combination with a refrigerating system of the type alternativelyemploying gas or electricity as power sources and in which cooling iseected by a refrigeration unit having a heat receiving part, of a gasburner heating means adapted to heat the heat receiving part, means forsupplying gas energy to said burner heating means, electrical heatingmeans adapted to heat the heat receiving part, means for conductingelectrical energy to said electrical heating means, and switching meansconnected to said gas energy supply means and to said electrical energyconducting means and adapted simultaneously to connect a first of saidenergy means to its associated heating means and to disconnect thesecond of said energy means from its associated heating means o'r toconnect the second of said energy means to its associated heating meansand to disconnect the first of said energy means from its associatedheating means, said switching means comprising an electric switch whichis coupled to said electrical energy conducting means and to saidelectrical heating means and includes a movable part for completing andinterrupting electrical continuity therethrough, said gas supply meansincluding a valve having a rotatable plug with a passage therethrough,and means coupling said rotatable plug to said movable part of saidelectric switch, whereby said plug opens said electric switch uponturning of said plug to a position opening said valve and said plugcloses said electric switch upon turning of said plug to a positionclosing said valve.

1I. In combination with a refrigerating system of the type alternativelyemploying gas and electricity as power sources and in which cooling iseffected by a refrigeration unit having a heat receiving part, of a gasburner heating element operable to maintain a flame burning in theatmospherer for producing combustion gases at an elevated temperatureand capable of functioning to heat the heat receiving part by heatderived from said combustion gases substantially at said elevatedtemperature, means for supplying gas energy in the form of a combustiblegas to said burner heating element, an electrical resistance heatingelement capable of functioning to heat the heat receiving part, meansfor conducting electrical energy to said resistance heating element, andmeans adapted to selectively connect either one of said energy means toits associated heating element whenever both electricity and gas areavailable as sources of power for the refrigeration system, saidlast-mentioned means comprising switching mechanism which is operable atwill and connected to said gas energy supply means and to saidelectrical energy conducting means and adapted simultaneously to connecta first of said energy means to its associated heating element and todisconnect the second of said energy means from its associated heatingelement or to connect the second of said energy means to its associatedheating element and to disconnect the hrst of said energy means from itsassociated heating element, said switching mechanism comprising valvemeans including a movable element connected to said gas energy supplymeans and electric switch means connected to said electrical energyconducting means and means including a movable member which forms aunitary part of said movable element for operatively associating saidvalve means and said eletcric switch means.

l2. In combination with a refrigerating system of the type alternativelyemploying gas and electrictity as power sources and in which cooling iseectcd by a refrigeration unit having a heat receiving part, `of a gasburner heating element operable to maintain a flame burning in theatmosphere for producing combustion; gases at an elevated temperatureand capable of functioning to heat the heat receiving part by heatderived from said combustion gases substantially at said elevatedtemperature, means for supplying gas energy in the form' of acombustible gas to said burner heating element including a valve havinga valve element movable at will to positions opening and closing thesupply of gas to said burner heating element, electrical heating meanscapable of functioning to heat the heat receiving part, means forconducting electrical energy to said electrical heating means, andmechanism adapted to selectively connect either one of said energy meansto its `associated heating element whenever both electricity and gas areavailable as sources of power for the refrigeration system, saidlast-mentioned mechanism comprising electric switch means which isconnected to said electrical conducting means and includes a partshiftable responsive to movement of said movable valve element, saidelectric switch means opening upon shifting of said part thereofresponsive to movement of said movable valve element to a positionopening said valve to prevent flow of electrical energy to saidelectrical heating means, and said electric switch means closing uponshifting of said part thereof responsive to movement of said movablevalve element to a position closing said valve l l 1 2 to allow flow ofelectrical energy to said elecrtcal heating UNITED STATES PATENTS means2,009,067 7/35 Mulholland 62-148 References Cited by the Examiner ggIennilng 62-489 The following references, cited by the Examiner, are of5 000:19'76 9/61 Kgl record in the ptented le of :this patent or theoriginal patent. ROBERT A. OLEARY, Primary Examiner.

